wheeler



2 Sheets-Sheet 1.

C. D. WHEELER. Sewing Machine Thread Tension.

Patented Nov. 9, 1858.

, xmbw 2 Sheets-Sheet 2. C. 0-. WHEELER.

- Sewing Machine Thread Tension.

No. 22.045. Patented Nov. 9. 1858.

. of the city, county, and State ofNew' York,

- in Sewing-Machines, of which the following is section of aWheeler &7WVilsonsewing-1nachine less freedom of motion on its axis is controlled riphery contains a sharp groove in which the -sheave, jams, so thatthe sheave is turned by the thread as the latter is drawn to the point where itjis used, and the tension or strai nupon resistance of "the friction-brake, which, when once adjusted-,Iemains constantly the same,

. plied tofregulate the tension of the thread pieces of hardenedsteeh-f: and i, contained- UNITED STATES PATENT OFFICE.

,c. '1). WHEELER, OF NEW YORK, N.

Specification torming part of Letters P atent'Nol 22,045. dated November (l, 1858.

T0 aZL whom it may concern Be it known that I, CALVIN D. WHEELER,

have invented a new and useful Improvement a full, clear, and exact description, reference being had to the accompanying drawings, in which v I a Figure 1 represents a vertical longitudinal with my improvement-applied thereto. -.Fig.. 2 represents a vertical transverse sectionof the; same machine at the line 00 m of Fig. 1, and Figs. 3 and 4 are sections of certain parts of the thread-tension detached fromthe machine.

My inventionhas reference to that portion of the mechanism of a sewing-machine by 'meansof which the tension of the thread is regulated; and its object is to produce-a uniform tension upon the thread without reference to the quantity of thread, whether large or small, which may be wound upon the spool.

My invention consists in interposing betweemthe thread-spooland the place where the thread is'used a sheave whose greater or by an adjustable,friction brake,and whos'epe' thread, which is passed partly round the the thread'dependsupon the greatehor less whatever quantity of thread be passed through themachinefl'. In the ,rnachine representedin the acconr panyin'g-i irawings iny improvements are apt 3' passes to the needle. The spool of thread is placed upon a spindle, a, ,which issecured-in a' convenient'position forf thepurpose to .one

shaft G'of the-needlearmdllf. i From this spool drag in the-present instance consists of two.'

in and supportedabya tubular' case,-

which is secured tothemeedleaarnr. One of 'these!, pieces, e,i s.-acted upon"bva; slight spring,'-o,'

which tends to force it toward the-othen'wliile .the other'for nsascrew-plug, i,which is screwed '1 into the case 0 and closes its end. The case has a transverse notch, g, out into its lower side atthe point'of'coutact of the steel pieces, and this notch extends about halfway through the case, so as to permit the thread to he introdu'ced between the faces of the steel pieces and to guide it across their centers. -.l.he thread from the drag passes to the groove in the sheave H. lit is necessary that the innermost part of this groove should be sharp, so that fine thread may be certain to jam in it; and as I have found it extremely dil'iicult to turn such a groove in a solid piece of metal, I'have found it expedient to construct the sheave of two disks, j 71, whose adjacent faces are turned to the proper shape, and which are riveted together. This sheave is mounted upon an axis, 'm, secured to the needle-arm. A friction-washer, Z, is mounted upon the same axis, to press against the side of the sheave and act as a frictionbrakc. This washer is prevented from turning with the sheave by flat-- tening a portion of the axis and making the hole in the washer of corresponding form. It is pressed toward the sheave by -nieans of a volute spring, at, whose tension is adjusted by. meanspf aniilled nut, 1', that is screwed upon .the axis, and can be readily turned hy the hand of 'theoperator.

' In order to enable the'apparatus to work for a length of time without cleaning or 011mg, 1

have found it expedient to interposea greased leather washer between thesheave and the shoulder s-of the aiis upon which .it turns,

and a second greased leatherwasher between the sheave and the spring-washer Z.

. In using the mechanism thusdescribed the thread is inserted in the notch of the drag.}:,

. and, is passed around the sheaveH inthe manner represented in Fig. 1, so that it nearly en'- circles it, after which it is passed to the needle.

lhe tension is regulated by screwing up the milled nutr to a greater or less extent,'thns forcing the spring to press the spring-washer toward the sheave with. greater or less force, andicaus'ing the washer to oppose a greater or less resistance to the turning of the sheave,

: which consequently holds back the thread with greateror less force. As the thread passes coristantlyaroundthe same circle in the groove,

and ,as the tension of the spring, when once ad justed, is constant, and as the actioirlof the] spring-drag upon the thread is alseinthe-pres eut instance constant, it follows that the'ten-S: sion of the thread will be same, ,whatever quantity be passed through the apparatus, and whether much or little be wound upon the spool. The office of the drag F is toprevent the slacking ofv the thread upo the rotating I regulating apparatus, and insur its close con-- tact therewith, which might .not occur if the; thread were conducted direetly from'the spool to the regulator, especlally if thethread should deliver from the spool too-freely. Any other apparatus which will fulfill this ofiice may be substituted for the one abovedescribed, andin place of interposin'g such a drag between the sheave and the spool or other source of thread,- 1

a p gmay bemade to act upon the spoolitself.

The apparatus thus descrlbeu may be IllQdi'" fied as circumstances may render expedient. It is applicablenot only to sewing-machines,

but toany purpose where thread, yarn, cord,

jor rope is to he deliveredwith a uniforin ten-' sion. If the cord be 1arge',-it' is not necessary that the groove should be so fine at its bottom, butit must besharp enoughto insure the jan1- ming oftlie cord-in it.

- embodi es my improvements, what I claim as my invention ent, is'- v The combination of .a sheave'whose groove is sharp, or so constructedthatthe thread may jam therein by a partial passage, around the control the movementuof the said sheave, substantially-as described." i

v In testimony whereof I have hereunto subtseribed my name.

v @A'L'v'm D. 'WHEELERI- "Witnesses: Z i a MYR0N BERRY,

S; W. DIBBLE.

Having thus described. the apparatus which f and desire to secure by Letters Bat-f sheave, with an adjustable friction-brake to 4 

